Electrical switch



Dec, 30, 1924. 1,521,432

J. F. CAVANAGH ELECTRI CAL SWITCH Filed April 24, 1924 reame Dec. 3o,1924.

, weer PATENT o1-*rica JOHN F. CAVANAG, F PROVIDENCE, RHODE ISLAND.

ELECTRICAL SWITCH.

Application filed April 24, 1924. Serial No. 708,718..

To all lwhom t may concern.'

l Be it known that l, JOHN F. CAVANAGH, a citizen of the United States,residing at Providence, in the county of Providence,

' State of Rhode lsland, have invented certain new and usefullmprovements in Electrical Switches, of which the following is 'aspecification.

This invention relates to electrical switches and consists inimprovements in the construction and method of operation of the same.

v A principal object of the improvement is to provide a simple, compactswitch of the so-called toggle type adapt/ed for various uses such as anignitionor lighting-switch for automobiles or as a panel-swltch forradio-apparatus.

Another object of the improvement is to provide a switch which may beattached to an instrument-board, panel or other support withoutrequiring screws or bolts to hold it and vhavin exterior means forclampin in place. i I

Another object of the lmprovement 1s to l provide a switch having aminimum number to manufacture.

Another object of the improvement is to provide a switch in which theoperatingmechanism is completely enclosed and the parts made proofagainst wear or deterioration, whereby to insure greater durability andalso to render the switch less liable to derangement or gettin out oforder.

Further objects of t e improvement are set forth in the followingspecification which describes a preferred embodiment of the invention asillustrated in the accompanying drawings. ln the drawings: I

Fig; 1 is a view of the switch in perspective showing it as attached toa anel; u

Fig. 2 is an-enlarged, longitu sectional view of the switch taken in thevertical plane of its axis; and

Fig.- 3 is a similar fragmentary, sectional view illustrating thecontacts ofthe switch in closed position.

Referring. to the-drawings, the present improved switch .comprisesessentially a vmain casin consisting ina tubular barrel or sleeve 2 aapted for insertion through an opening in a panel, board or othersupport it thereto.v herein illustrated the barre or sleeve 2 isprovided at one end with a head or flange 3, preferably constructed inthe form of a hexagonal nut, and with exterior screw-threads 4 on itsbody for engagement with a clamping plate or washer 5. Referring to Fig.1, the barrel or sleeve 2 is inserted through a suitable hole 6 drilledin the panel 7 or other support with its head 3 abutting the facethereof. rllhe plate or washer is then screwed onto the barrel or sleeve2, and by turning the latter by means of its nut or head 3 theclamping-Washer 5 will be bound tightly against the rear of the panel tofasten the switch securely thereto. rlhe washer or plate 5 may beprovided with an odset arm or lug 8 having 'a threaded hole forreceiving a binding-screw 9, to which is attached one of the terminalwires 10 of the circuit in which the switch is used.

rlhe barrel 2 is preferably of cylindrical shape with a longitudinalbore 11 extending throughout its length and reduced slightly in diameterat its outer end to form an interior shoulder 12. A. relatively thinsleeve 14 of insulating-material, such as a rolled -stri of liber or thelike, is inserted in the bore 11 with its forward end abutting theshoulder 12 as shown in Fig. 2.

At the rearward end of the barrel 2 the bore 11 is slightly enlarged toadapt it to receive a' fiber washer 16 which abuts a shoulder 17 formedby the enlarged counterbore 15. 'llheroutercircumference of the barrel 2is turned down or reduced in diameter at this .end to form a relativelythin. neck 18, which is spun or flanged inwardly to overlap the rims ofthe washer 16 to hold it in position at the end of the barrel abuttingthe shoulder 17 in the bore 15 A metal plug 20 projecting through thehole in the fiber washer 16 is formed with an enlarged head 21 receivedWithin the main bore 11 of the barrel 2. Preferably, the head 2l lis ofless diameter than the interior of the insulating-sleeve 14: and isformed at its end with a peripheral dange f or `lin 22. 'lhe flange 22.at they inner endof the-,plug20 lls the space within the interior of theinsulating-sleeve 14 and serves as a rest-or abutment for the end of ahelical l thereof to hold the washer in place against the inturnedportion `of the neck 18 at the end of the barrel 2. Through this simpleconstruction the metal plug 20 is fastened.

lirmly in place at the end of the bore 11 of the barrel 2and efectuallyinsulated therefrom to adapt it to form one terminal of the circuit inwhich the switch is used. A binding-screw 26 is threaded into a tappedhole in the plug 20 to provide a means for at- A taching a wire 27 orother conductor thereto as shown in Fig. 1.

At the opposite or outer end of the barrel 2 is a metal plug or plunger30 litted to slide freely within lthe bore of the sleeve 14, andinsulated thereby from the metal of the barrel. The plunger 30 is formedat its outer end with an axially-projecting studl o teat 31 which servesas a contact-point for the switch-arm or lever 35. Surrounding thecontact-stud 31 is a flat washer 32 of fiber or other suitableinsulating-material which entirely covers the outer end of the plunger30 with the exception of the end of the contact-stud.

The switch-lever 35 may be of any suitable, form and, as herein shown,consists of a tapered rod or arm 36 having an integral ball at eitherend. The ball 37 at the butt end of the arm 36 is of a diameter to adaptit to it the reduced outer end of the bore 11 in the barrel'2 to allowit to turn freel therein. A cross-pin 39 driven through suitable holes.in the sides of the enlarged head or nut 3 on the barrel 2 passesthrough an axial hole in the ball 37 to hold the latter in place in thebore 11 while also serving as a pivot for the lever 35 to adapt thelatter to rock vertically up and down or back and forth horizontally inaccordance with the positioning of the switch. The ball 37 is truncatedand recessed by drilling it with a hole 40' of sufficient diameter toadapt it to surround the contact-projection or stud 31 at 4the end oftheplunger 30 without contact therewith when the lever 35 is alined withthe axis of the barrel 2 as illustrated by full lines` in Fig. 2. The.drilling or recessing of the enlarged butt end Vor ball 37 of the lever35 with the opening 110 provides a relatively fla-t rim or seat on thisside of the ball which, when the plunger 30 is urged outwardly by itsspring 25, bears against the face of the insulatingwasher 32 and tendsto hold the switch-lever in perpendicular relation. With the lever 35,in this position `the switch is open, the butt end or ball 37 of thelever being insulated from the plunger 30 by the Washer 32 and thecontact-stud 31 being clear of the rim of the openin 40 in the ball.When the lever 35 is rocke on its pivot 39 to tilt it into inclinedposition, as illustrated in Fig. 3, the recess 40 will be displaced toone side and the solid portion of the ball,

lthe contact-elementsv of the switch 37 will be carried-into engagementwith the stud 31 to close the contacts of the switch in the manner ashereinafter` more fully Lexplained, the methodl of operation of thecomplete device. being as\follows: v K

With the switch installed in the manner as. previously described oneconductor or wire 10 of the electrical circuit is fastened to thebinding-screw 9 `and is 'thus electrically -connected to theswitch-lever 35 through the washer 5 and barrel 2. The opposite wire 27of the circuit is connected to the plug 20 by means of the bindingscrew26, the plug being insulated from the barrel 2 by the liberlining-sleeve 14 and washers 16 and 23, but electrically connected tothe plunger 30 through the helical spring 25. In this way the lever 35forms one terminal of the circuit andthe plunger 30 the other terminal,the ball 37 on the lever and the stud 31 on the plunger providing thecontact-points for closing the circuit. If desired the switch lever 35may be enameled -or otherwise covered with insulation, or the fingerportion of the lever may be constructed of liber, bakelite, vulcanizedrubber or the like with a metal ball-end attached thereto.

With the lever 35 in the position illustrated in Fig. 2, the opening orbore 40 in Kthe butt end of the lever prevents its contact with the stud31 on the plunger 30 as before explained, and the pressure of theplunger normally maintains the lever in this relation with the switchopen. To close the switch a slight pressure is exerted on the lever 35to rock it on its pivot 39, the

ly to compress the spring 25 and the solid portion of the ball 37 beingthus brought into contact with the stud 31 as shown in Fig. 3. The lever35 will then be held in this position by the. frictional pressure of theplunger on the side of the ball 37 under the action of the spring 25until' it is thrown back into open position again. With the switchclosed the current flows from the wire 10 through the washer l5, barrel2 and lever 35, and thence through plunger 30, spring 25, plug 2O to thewire 27 constituting the opposite lead of the circuit. The

switch-lever or handle 35 snaps back and forth to open and close thecontacts under maintained in on and off position against accidentalmovement.

It will be observed that my improvement provides a particularly simple,compact and eflicient electrical switch having its operating-mechanismentirely enclosed andmade proof against deterioration from wear orgetting out of order through derangement of its parts. The peculiarconstruction of rovides for la wiping engagement there tween,l

thereby insuring a positive electrical connection and also tending tomaintain the contacts clean and bright. rllhe elements of the switch arefew in number and adapted for economical production and assembling withvery little labor, whereby the complete device may be manufactured at arelatively v low cost. ln addition, the switch is attractive inappearance and capable of being applied to a panel or other support bysimply inserting its barrel or casing through an opening. therein,without requiring screws, bolts or other separate fastening-means forholding it in place.

While li have herein shown and described a preferred form of the deviceas illustrative of the improvement, it is to be understood that variousmodifications may be made in the structure and arrangement of its partswithout departing from the spirit or scope of the invention.

Therefore, without limiting myself in this respect, lt claim: i

1. An electrical switch comprising a casing, a yieldable contact-elementin said casing having its contact face protected by insulating-materialwith the exception of a relatively small area thereon, and a leverhaving a recessed portion bearing against the insulated face of thecontact-element with its recess adapted to surround the contact areathereof to prevent electrical connection therebetween, said leveradapted to be moved into position to displace its recess to engage itssolid portion with the eX- posed area of the contact-element.

2. An electrical switch comprising a yieldable contact-member having abearing face with a contact-projection thereon, a

covering of insulating-material on the face of the contact-membersurrounding the contact-projection, and a lever having a re- ,cessedportion adapt/ed to bear against the insulated face of thecontact-member with the contact-projection enclosed within the recess toprevent electrical connection therebetween, said lever adapted to beshifted in position to displace its recess and wipe its solid portionacross the contact-projection to close the circuit throu h the switch.

3. ln an electrical switc ,the combination of a yieldablecontact-element having a relatively at face with a contact-projectionthereon, a covering of insulating-material overlying the face of thecontact-element surrounding the contact-projection, and a lever having atruncated enlargement at its end against which the contact-element bearswith a recess therein for receiving the contact-projection withoutcontact therewith,

of a contact-element having a bearing-face provided with a centralcontact area surrounded by insulating-material, a switchlever having anenlarged recessed end adapted to bear against the contact-element w1ththe contact area thereof enclosed within its recess to preventelectrical contact between said element and the lever, and resilientmeans for urging the contact-element against the end of the lever tonormally hold the latter in certain relation therewith while permittingsaid lever to be rocked to displace its recess whereby its solid portionwill malre contact with the exposed area of the contact-element.

5. lln an electrical switch, the combination of a tubular barrel, acontact-plunger slidable in said barrel and formed with a restrictedconta-ct area surrounded by insulating-material, a lever having yatruncated recessed end adapted to bear against the insulating-materialon the contact-plunger with its recess surrounding the contact areathereof, and a spring in the barrel acting against the contact-plungerto cause the latter to frictionally engage the truncated end of thelever to maintain the latter in position with the contact pointsdisengaged while allowing the lever to be shifted to displace the recessto bring its solid portion t into engagement with the contact area ofthe plunger.

6. lin an electrical switch, the combination of a tubular barrel, alever pivoted in the opening at one end of the barrel and pro- 1 videdwith a truncated end having a recess therein, a metal plunger slidablein the barrel and formed with a contact-stud prowasher overlying the endof the plunger surrounding the contact-stud, and a spring in the barrelacting against the plunger to urge the latter forward with its washerbearing against the rim of the recess in the truncated end of the leverwhile permitting the lever ,to be rocked to engage its solid portionwith the contact-stud on the plunger.

7. lln an electrical switch, the combination of a barrel having an axialbore, a lining of insultating-material in said bore, a lever pivoted inthe bore at the outer end of the barrel and provided with a truncatedballend having a circular opening therein, a plunger slidable in thebore of the barrel and provided with a contact-projection on its outerend of a diameter less than the diameter of the opening in the lever, awasher of insulating-material overlying the end of the plungersurrounding its contact-stud to adapt it to bear against the rim of theopening in the ball of jthe lever, a.v spring in the bore of the barrelactin to press the-plungl er against the end of t e lever, and means forconnecting the lever and contact-plunger to the opposite ends ofan'electrical circuit.

8. In an electrical switch, the combination of a tubular barrel havingan axial bore, a lining of insulating-material in said bore, a plug atone end of the bore insulated from the barrel and forming one terminalof the electrical circuit, a plunger at the opposite end of the borehaving a central contactprojection, a washer of insulating-materialoverlying the end of the plunger surrounding the contact-projection, anda lever pivoted at the end of the bore in the barrel and provided with aspherical enlargement formed with a recess having its rim adapted tobear against the washer on the plunger, and a spring forl pressing theplunger against the recessed end of the lever to maintain the latter inaxial alinement with the plunger while-adapting it to be rocked to wipethe solid portion of its spherical end across the contact#projection onthe plunger.

9. In an electrical switch, the combination of a tubular barrel havingscrew-threads on its exterior and an enlarged head at one end, a washeradapted to screw on to the barrel to secure it in position projectingthrou h apanel with its head abutting the face t ereof, a plunger-slidable in the bore of the barrel and formed with a centralcontact-projection, a washer of insulatingmaterial overlying the end ofthe plunger surrounding its contact-projection, a lever pivoted at theend of the barrel and provided with a spherical enlargement at its endhaving a recess therein forming a trun- "cated portion adapted to bearagainst the l washer on the end of the plunger, and a spring in the boreof the barrel for pressing the plunger against the truncated end of thelever to normally hold the latter in axial alinement with the plungerwhile permitting it to be swung into position to bring the solid portionof its end into engagement with the contact projection.

10. In an electrical switch, the combination of a tubular barrel havin ahead at one end and screw-threads on 1ts exterior,

a washer adapted to be screwed on to the .I

ward end covered with insulating-material surrounding thecontact-projection, a lever pivoted at the end of the barrel andprovided with a truncated spherical enlargement adapted to bear againstthe insulated end of the plunger and formed with a recess surroundingthe contact-stud, and a spring acting between the plug and the plungerto urge the latter outwardly to cause it to bear against the sphericalend of the lever to frictionally hold it in adjusted relation whileallowing it to be rocked into on and ofl7 position.

11. In an electrical switch, the combination of a tubular barrel, alining of insulating-material in the bore of the barrel, a metal plug atone end of the bore, an insulating-washer surrounding the plug and se.

cured in the end of the bore of the barrel to hold the plug in place, alever pivoted at the opposite end of the bore of the barrelA andprovided with a truncated spherical end having a circular recess, aplunger slidable in the bore of the barrel and formed with a studprojecting from its end within the confines of the recess in the lever,a washer ot insulating-material overlying the end of the plungersurrounding the contact-stud to normally prevent contact'between thelever and the plunger, and a spring in the bore of the barrel acting onthe plunger to press it against the truncated spherical end of thelever.

In testimony whereof aix my signature.

JOHN F. CAVANAGH.

aol

